The light-fastness of simple mono-azo dyestuffs on polyamide fabric was studied. Examination of the characteristic fastness-grade curves give information about the relation between the size distribution of the dye particles on the fiber and its concentration. The fading rate of the dyestuffs as a function of the time of irradiation leads to evaluation of the fading-reaction order. The shape of the fading-rate curves and the characteristic fading curves are used to diagnose the physical state of the dyes in the fiber. ' This note .briery report}1m the determination of the light-fastness properties of some simple mono-azo dyestuffs and the 'relationship between their light-fastness properties and their physical state in polyamide fabric.The mono-azo dyestuffs I to VIII (see Table I) were prepared by diazotization of the proper amine and coupling in alkaline medium with phenol. Their purity was determined by thin-layer chromatography using silica gel layers and chloroform-acetone (9:1 v/v) as eluent.The polyamide fabric (Nylon 6), 144.7 g/m2 (from El-Nasr fot Spinning, Weaving, and Knitting Mill, El-Shourbagy, Cairo) was not subjected to any chemical treatment and was free from optical brightening agents.The fabric was dyed by the conventional exhaustion method in a laboratory dyeing apparatus. Seven concentrations were selected for each dyestuff. The actual concentrations of the dyestuffs on the fabric were calculated by extraction, using a mixture of chlorobcnzehe and acetic acid (1:1 1 .v /v) followed by an absorption-spectral method [9]. ' Irradiation of the dyed fabrics was done by means of two sources: daylight and carbon-arc Fade-Ometer. Exposures were for periods ranging from 20 to 200 h. Rjflectance spectra were recorded in the region from 400 to 700 jAm for all the dyed fabrics at different' concentrations. The spectra were also recorded for both exposed and unexposed fabrics.' Table I shows the dyestufl's, the references used for their preparation, and their, light-fastness. It was noticed that dyes I, II, and IV are fast to light nd carbon-arc lamp, while, for dye I I I, the light-fastn s ~ B varies from 3 to 4, and for dye VII it varies from 6 to . I)yes V, VI, and VIII showed a duller change of color accompanied by an increase in color intensity. After exposure for more than 80 h, fading had occurred and decrease in color intensity took place.~ ' Fading seems to depend to a considerable extent upon the physical state in which the dye exists in the fiber [1-l, 11].' For this purpose a study was done on the above dyestuffs showing the ,following relationships : , . 1. dh. ra eristic fastness-grade (CFG) curve, a relation tween the light-fastness of the dyestufl's and their concentrations on the fabric. 2. The fading-rate curve, a relation between the reflectance (%) of the dye on the fabric and the time &dquo; of its exposure to irradiation. -' 3. Characteristic-fading (CF). curve, a relation between the time required for 10% loss of the initial dye cdntent and the initial dye concentration in the ...
Eleven samples of lipid from cottons from different geographical locations have been examined by laminar chromatography. Every lipid contains the same 16 components and, although the proportions vary, the differences are-not sufficiently large or consistent to enable the source to be identified. The chemical classes to which the major components belong have been determined.
Die Metallkomplex-bildenden Farbstoffe 5a-h entstehen durch Kupplung von 2-Methoxy-, 2-Hydroxy-und 2-Carboxy-aryldiazoniumsalzen rnit 6-Hydroxy-chrysen (1) in Pyridin. Chrysenchinon (2) wird rnit o-substituierten Arylhydrazinen zu den Metallchelat-bildenden Azofarbstoffen 6a-f kondensiert. ~ Entmethylierung der 5-Hydroxy-2-methoxy-arylazo-Farbstoffe 5 b und 6b rnit Kobaltnitrat in Pyridin fuhrt zu den Dihydroxy-azo-Verbindungen 5h und 6h. 0'-Hydroxylierung der Monohydroxy-azo-Farbstoffe 3, 7 und 8 ergibt Gemische von Ausgangsmaterial und den gewunschten Dihydroxy-azo-Farbstoffen 5g, 5h und 6h.Nach Metallkomplex-bildenden Farbstoffen des 9.1O-Phenanthrenchinonsz), des Naphthochinons-(l.2)3), des Acenaphtheiichinons4) und des Isatinsl), beschreiben wir jetzt, von 6-Hydroxy-chrysen (1) und Chrysenchinon-(5.6) (2) ausgehend, Metallkomplex-bildende Azofarbstoffe des Chrysens.
The synthesis of reactive rotproofing agents based on dichloroand monochloro-s-triazines and their application on cotton fabric has been attempted. The combination of both chromophoric and antimicrobial properties in the same molecule was achieved by development of reactive cotton with the appropriate amines. ,
The effect of the basic skeleton of the molecule as well as the type and number of nucleophilic groups on fixation of dyestuffs on cellulosic fibers using hexahydro-1,3,5-tri-acryloyl- s-triazine is studied. It is shown that the different groups react in the order amino group > imino group > hydroxyl group. Presence of three or at least two nucleophilic groups is generally essential for higher degree of fixation.
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